This version, model 4053 3, features a conversion table on the back. Like the rule itself, many of its conversions bear little relevance to life in 2013.

The International Slide Rule Museum tells us that in 1967, Keuffel & Esser Co. commissioned a study of the future, predicting that Americans in 2067 would live in domed cities and watch 3D television. “Unfortunately for the company, the report failed to predict that slide rules would be obsolete in less than ten years, replaced by the pocket calculator.”

Still, it’s easy to believe that Charles Higgins, a Mathematical Club member, probably made good use of this tool in 1916. And while we in the NCC Gallery can’t fully appreciate its mathematical value, we certainly do appreciate its historical value.